In the wireless communication system, FDD (Frequency Division Duplexing) mode and TDD (Time Division Duplexing) mode have become two mainstream communication modes at present. Since many operators have both FDD and TDD licenses, there are urgent needs to deploy the two systems, and high demands are made in terms of simplicity, unity, as well as volume and weight of the deployed radio frequency unit. Currently, there are two schemes for the deployment of a dual-mode system. One is to achieve a shared antenna feeder scheme via external devices. As shown in FIGS. 1, 01 and 04 are receiving filters in the FDD frequency band, 02 and 05 are transmitting filters in the FDD frequency band, and 03 and 06 are filters in the TDD frequency band, and this scheme connects the two systems of two separate FDD and TDD radio frequency units together through an external multiplexer, but this scheme has difficulty in the engineering installation, and the cost is high. The other is a channel independent mode. As shown in FIG. 2, the receiving filter 01′ in the FDD frequency band, the transmitting filter 02′ in the FDD frequency band and the filter 03′ in the TDD frequency band are combined together, and this scheme only physically splices the TDD circuit and the FDD circuit together (for example, on one circuit board), without sharing the transmitting and receiving channels, and only places the two systems in the same housing, with the externally embodied form thereof being a radio frequency unit but the essence thereof being still two sets of independent systems.